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What is Z-axis Location Technology And How Does it Work?

In any emergency response, the most sought-after resource is timely information. The more data available to decision-makers, the better-informed they'll be when making critical life safety decisions.

In the two decades since the terrorist attacks on September 11, emergency response technology has seen rapid advancements, including the development of dedicated public safety communication solutions, drones for aerial surveillance, vertical axis location technology—Z-axis data, and more.

What is Z-axis data?


Reference points on a Z-axis determine the vertical location of an individual or object, as opposed to the horizontal, ground-level X-Y axes. In the public safety context, the Z-axis will give first responders critical information about the location of an individual in a high-rise building.

With the addition of the long-awaited Z-axis data point, first responders can locate victims with increased accuracy, while incident commanders are able to monitor crews for safety, or track law enforcement officers searching the floors for a suspect.

What is Z-axis location and how does it work?


To determine Z-axis location, barometric sensors found in most cell phones measure the device's vertical height above ellipsoid (HAE) and combine the information with other device metrics, such as GPS and Wi-Fi access points, to provide a relative vertical location. The information is relayed to 9-1-1 telecommunicators from the wireless device and then transmitted to emergency responders.

In 2015, the Federal Communications Commission (FCC) tasked the major mobile network carriers in the U.S. with improving Z-axis identification for use in 9-1-1 calls, implementing a 2018 deadline for test data.

In 2020, following the network carriers' success of the location technology testing phase, the FCC required that Z-axis data reported by carriers be within +/- 3 meters (or within one floor) of 80% of indoor wireless 9-1-1 calls.

In June 2022, the Cellular Telecommunications Industry Association (CTIA), which represents Verizon, AT&T and T-Mobile, announced the carriers were successfully providing the Z-axis location during 9-1-1 calls—a breakthrough for urban emergency operations.

How Z-axis location technology will enhance emergency response


As a majority of the annual 240 million 9-1-1 calls in the U.S. are via wireless devices, utilizing Z-axis solutions will help emergency crews cut down on response times, increase situational awareness and give incident commanders another data point to consider when making life and death decisions.

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Z-axis solutions for crew tracking


One of the most anticipated benefits of Z-axis technology is the ability to track the vertical location of emergency responders—a feature seen as a "must-have" for public safety professionals, emphasizing the critical importance of location tracking within large vertical structures.

Vertical location technology can help incident command track the locations of teams within a building. During a mayday event, fire crews can use Z-axis data to determine the location of a downed firefighter faster, allowing a rapid-intervention team to quickly enter the structure and extract the firefighter.

Additionally, incident command can see where other crew members are in relation to the mayday event and advise crews to avoid the area or to evacuate the structure.

Locating a search and rescue victim using Z-axis solutions


In an emergency, there are many reasons why 9-1-1 callers may be unable to share what floor they're located on. They may be injured or sick, or need to stay quiet for fear of being heard by a dangerous assailant, or they may simply not know. Prior to the development of Z-axis solutions, rescue crews would need to search a building floor by floor—a tasking, time-sensitive process, potentially delaying life-saving care.

With the addition of Z-axis information, crews can narrow their search location to a specific section of the building, eliminating the need to go floor-by-floor.

Even in a single-family home with multiple floors, vertical location data gives first responders a better starting point to find a victim and, in the case of a fire, more time to safely make it out of the structure before a collapse.

Adding Z-axis data to the XY plot points essentially provides a vertical map for first responders, removing a large unknown from the emergency scene and giving a fuller picture of the situation, potentially saving untold lives.

Benefits of Z-axis location technology during a multi-agency response


During a major disaster situation or emergency operation, multiple different agencies will be on site working on different aspects of the scene. Using Z-axis location technology, incident commanders can track multiple crews using situational awareness solutions.

In the event of a hostage situation, law enforcement units may be moving through the building looking for the suspect, using the app to relay information about the shooter's location in relation to the officers' Z-axis data. With the additional insight, incident commanders could send in tactical EMS crews to begin identifying and removing victims from the scene, potentially saving additional lives as a result.

The ability to track the vertical location of multiple crews also creates a more organized emergency scene and eliminates time-consuming check-ins over the radio as incident commanders attempt to visualize a crew's location before deciding on next steps in the absence of vertical location data.

Life-saving technology requires a reliable network



Z-axis location is a breakthrough technology for the public safety industry, providing a critical data point that incident commanders can use to both locate victims more efficiently and monitor the safety, speed and strategy of emergency crew operations. Z-axis location technology can provide a vital piece of the incident scene puzzle—if first responders and decision-makers on the ground can rely on the data to be there when they need it.

If ground crews are having to wait for vertical location data to arrive before beginning a search and rescue operation, it negates the time saved by incorporating the data itself. For emergency crews to utilize Z-axis data to the fullest, teams need to know it will be consistently available in necessary situations.

Learn how Verizon Frontline's advanced 5G network for first responders prioritizes the needs of public safety with reliable connectivity for emergency response technology.

The author of this content is a paid contributor for Verizon.
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